This invention relates generally to a grommet strip for covering an exposed edge of a wall and, more particularly, to an electrically insulating grommet strip for covering the exposed edges of openings in electrical equipment housings.
Electrical equipment housings frequently possess openings for the passage of electrical wires. Generally, such openings are equipped with grommets or bushings that cover and insulate the exposed edges of the openings. A common grommet is made of rubber or a similar resilient material and consists of a pair of annular spaced apart flange portions internally joined by a cylindrical portion. The cylindrical portion projects through an opening and the flange portions engage the peripheral wall portions thereof. Disadvantages of such grommets include the requirement for large inventories to accommodate openings of various size, and their inapplicability to openings of other than circular shape.
The above problems are somewhat alleviated by a grommet strip having a flat, elongated base from opposite edge of which project longitudinally spaced apart pair of fingers. The strip can be cut to desired length and then applied to an opening with the base engaging the edge of the opening and the fingers engaging peripheral portions thereof. Such a grommet strip is disclosed in British Patent No. 849,761. However, certain disadvantages persist for even the above described grommet strip. For example, the installation of the grommet strip into openings of complex shape requires the use of an adhesive and is, therefore, quite labor intensive.
Improved grommet strips are disclosed in U.S. Pat. Nos. 4,769,966 and 5,343,669. Those grommet strips comprise resiliently coated spring tempered substrate strips which can be securely mounted over an exposed edge of a wall without the use of adhesives. However, the multiple-axis flexibility of the grommet strips is limited so as to prevent their use over openings formed by non-cylindrical, tubular wall sections used in applications such as aircraft.
The object of this invention, therefore, is to provide an improved grommet for covering the exposed edges of openings in electrical housings.